1. Field of the Invention
This invention relates to the field of data processing systems. More particularly, this invention relates to the field of e-mail filtering within such data processing systems.
With the rise in the use of e-mail as a communication mechanism, this has been accompanied by a rise in the occurrence of unsolicited and unwanted e-mail messages. These so-called “Spam” messages cause a number of problems, such as consuming physical network and processing resources as well as wasting the time of the recipients in dealing with these messages in their inbox.
2. Description of the Prior Art
It is known to provide e-mail filtering mechanisms that apply predefined rules to received e-mail messages in order that Spam messages may be identified and automatically deleted. These existing system often work on content filtering with rules based on regular expressions applied to all inbound messages. A significant amount of unwanted e-mail is generally still able to pass through such systems because the filtering rules are not normally maintained to a high degree and tend to lack flexibility to deal with an ever changing problem.